The figure shows a low level cloud as seen from airborne measurements carried out by Communication Research Laboratories' SPIDER 94 GHz radar. The upper panel shows the intensity of the radar echo (reflectivity). The middle panel shows the velocity of the particles inside the cloud as observed by the radar (Doppler). The lower panel shows the intensity of the radar echo from the surface of the sea. The dip in tbis panel is due to the attenuation on the radar echo due to the water in the cloud. These measurements will be explored to develop an algorithm to retrieve the water content in low level, liquid water clouds.